{"instruction": "You are an expert in named entity recognition. Please extract entities that match the schema definition from the input. Return an empty list if the entity type does not exist. Please respond in the format of a JSON string.", "schema": ["Chemical", "Disease"], "input": "After the end of the treatment , the number and the size of induced PAS positive preneoplastic foci was significantly reduced when PB was given simultaneously with DEN for 4 and 6 weeks ."}
{"Chemical": ["PB", "DEN"], "Disease": ["preneoplastic foci"]}